Invariance of light speed and nonconservation of simultaneity of separate events in prerelativistic physics andvice versa in special relativity

Abstract

Light speed invariance and nonconservation of simultaneity of separate events are often considered as peculiar properties of Einstein's special relativity (SR). On the contrary it is possible to formulate SR so that simultaneity be conserved and light speed be no longer invariant.Vice versa it is possible to formulate prerelativistic, or Galilean physics (GP), so that simultaneity be no longer conserved and light speed be invariant. Simultaneity conservation (or not) and light speed invariance in both GP and SR depend on the arbitrary way in which the clocks of reference systems are synchronized. This arbitrariness leads to infinite possible coordinate transformations (T) in GP, the simplest and most convenient of which are the GalileanT. Similarly there are infinite possibleT in SR and the LorentzT is one of the two most convenient ones. The other suitableT is that of Ives-Tangherlini which implies absolute simultaneity and a noninvariant speed of light. This allows a revival of the ether, although no longer considered as a classical fluid, but as the electromagnetic field radiated by all particles of the universe. This ether should produce the slowing down of clock rate and longitudinal shortening of the moving rods which are the peculiar properties of SR.